Method of and apparatus for trimming grinding wheels



Sept. 8, 1931.

I J. WILBERZ 1,822,073

METHOD OF AND APPARATUS FOR TRIMMING GINDING WHEELS I Filed March 20. 1928 l Patented :omas or Hmmm, aannam ximian or un mm1-Us roi;l 'rmmsfcnmnnrs mais .Application mcd Iaroh 20, .1928,'8eria1 I o. 883,180, and in Germany` lay 1927.

My invention relates to amethod of and reciprocation, -g is a trimming tool which apparatus for trimming grinding wheels, more particularly the wheels of grinding -machines, while operativel mounted on the ma-` 5 chine. It is an object o -my invention to rovide means for making up for the g'ra nal reduction in the diameter ofthe grinding wheels. To this end I provide a mechanismby which thegrinding wheel is retracted from- 0 /the workpiece laced in Contact with the trimming tool an returned into contact with it in proper position, and means for increasing the stroke of this mechanism in proportion to the reduced radius of the grinding wheel. Trimming of grinding wheels is required periodically in order to remove eccentricity due to unequal wear or to maintain a 4predetermined erom-sectionof the grinding wheel A has already been- 'suggested to trim grinding wheels on the grinding machine byo which is applied-.to The diameter of the 1 means of a trimming to the inding wheel.

'grin ing wheel is reduced by the trimming and in order to make upfor this, itis necessary to place the shaft of the 'nding wheel nearer to the workpiece. l flhls was effected heretofore either by and, -requiring precision instruments, or by automatic means, requir- 4 ing electric control.. InI the former case the Y' personal factor and the accuracy, of the measuring instruments play an in iortant part, while in the latter case a com licated and comparatively expensive switc ing mechanism must be relied on.` l In the drawings ailixed .to this specification' and forming part thereof an apparatus em'- bodying my invention as applied to a grind-` ing machine is illustrated diagrammatically by wa of. example. l Intedrawings Fig. 1 is an `e evation of a grinding machine equipped with myimproved apparatus, Fig. 2 is a plan view of the machine,p a rtly lin section onthe line II--II in Fig.`1. Referrin to the drawings, a is a inding 'f wheel whic is rotatably arranged 1n a carriage .6, afarisga pulley onthe shaft of the grinding wheel, c is theframe of the machineeon which the carriage` is arranged for Icran '.posite direction until it is arrested-by the to the, tool. No measuring is required, the personal :factor and the accuracy of measuring instru- I' 'ments are eliminated and it is not vnecessary secured on the frame c, and h is the workpiece. lThe grinding wheel a is thus arranged intermediate the tool 'and the workpiece. v -Means for alternately applying the wheel`I a to the tool g and the workpiece h byreciprocating the vcarriage b comprise a handled, checks z' on the frame which permit turning of the handle through an angle notexceeding degs., a shaft d supported in a suitableA`- bearing cf of the frame c, a circular crank df on the inner 'end of the shaftd, a crank pin evinserted in La slot. of, the crank and 1 equipped with a square block le to engage be- 'tween two parallel projections b on the carl riageb,'and a threaded spindle f by which the 15,61 -is reciprocated in the' slot of thel By turning the handled to the!4 left as shown in Fig. 1 until itis arrested by one of- `'m' the checks z', 'thewheel a is withdrawn from the workpiece h and applied to the trimming tool g and by turning the Ahandle in the o pother check i, .thegrindng wheel is withi drawnl from the tool q and applied to the workpiece Ji. The radius of the crank reuired for reciprocatin the carriage bis a n ction .of the graduay decreasing radiusl of the grinding wheel a and may be varied-'f by disp acilig the in ein the slotof the crank d b means of t e spindle f; In this inan- 11erl t e radius o'f the crank, and the stroke f of the carriage b, are increased as the radius of the grinding wheel decreases. When th'- grinding wheel has been trimmed, the handle d'is returned to its initial position as4 shown in Fig. 1 and the grinding wheelis 5 again in the proper position with respect to rely on the automatic electrical devicereferred to. I wish it to; be understcod'that I do not f desire to be limited to theexact details of method andapparatus described for obvious modifications will occur to a person skilled inmate.

I caxilmzf l. apparatusor trimming 'n 1 wheels comprising a frame, a slidelilsipte to reciprocate on said frame a'crank carried 5 to rotatein said frame, a crank pin on said crank adapted to impart reciprocation to said slide, means for rotating said crank, means for varying its radius, a grinding wheel o n said slide, and a trimming tool ar- 10 ranged on said frame in line with said grinding Whee1.- j

2. An apparatus for trimming grinding Wheels comprisinga rame, a slide adapted to reciprocate on said rame a crank carried l5 to rotate in said frame, said crank having a slot, a bracket in said slot, athreaded Spindlekoperatively connected with said bracket so'as to vary; its position in said slot, a pin on said bracket operatively connected with Y )20 said slide so as .to impart reciprocation thereto upon rotation of said crank, a grinding wheel on said slide, and a trimming tool arranged on said frame in line with said grinding Wheel.

25V In-testimony whereof I aiiix my signatnre,

JOHANNES W'ILBERZ. 

